Hot melt adhesive compositions

ABSTRACT

Hot melt adhesive compositions having improved bond aging characteristics are disclosed. The compositions include blends of (a) certain block poly(ester-amides) having about 5 to about 55 weight percent of amorphous polyamide segments and about 95 to about 45 weight percent of crystalline polyester segments with (b) a vinyl aromatic polymer.

United States Patent Jackson, Jr. et al.

[ Sept. 23, 1975 HOT MELT ADHESIVE COMPOSITIONS Assignee: Eastman Kodak Company,

Rochester, N.Y.

Filed: Jan. 8, 1974 Appl. No.: 431,650

[52] U.S. Cl...... 260/22 D; 117/122 PA; 117/161 P; 117/161 UZ; 156/331; 156/332; 161/214; 260/23 P [51] Int. Cl. B32B 15/08; CO9] 3/14 [58] Field of Search 260/22 D; 117/122 PA; 156/331, 332; 161/214 [56] References Cited UNITED STATES PATENTS 3,650,999 3/1972 Martins et al 260/22 D 4/1972 Caldwell et a1. 260/873 3/1974 Jackson et a1. 260/22 D Primary E.\'aminerRonald W. Griffin Attorney, Agent, or FirmJ. Frederick Thomsen; Daniel B. Reece, 111

[57] ABSTRACT l-lot melt adhesive compositions having improved bond aging characteristics are disclosed. The compositions include blends of (a) certain block poly(esteramides) having about 5 to about 55 weight percent of amorphous polyamide segments and about 95 to about 45 weight percent of crystalline polyester segments with (b) a vinyl aromatic polymer.

18 Claims, No Drawings HOT MELT COMPOSITIONS This invention relates generally to hot melt adhesives, and more specifically, this invention relates to hot melt adhesive compositions having improved bond aging characteristics as well as other important properties.

Hot melt adhesives are of importance because of their speed of application compared with other types of adhesives. No solvents must evaporate, no curing must take place, and strong adhesive bonds are obtained as soon as the adhesive cools. Polyesters and poly(esteramides) have been found useful as hot melt adhesives. Many polyesters have low adhesive strength, particularly peel strength, on various uncoated substrates such as aluminum, copper, steel, glass, etc., and on substrates coated with various materials, such as polyepoxide resins, vinyls, phenolics, alkyds, acrylics, etc. Another problem often encountered is that some hot melt adhesives lack the ability to maintain high adhesive strength after aging as well as the ability to maintain high bond strength under relatively hightemperature conditions. Moreover, many hot melt adhesives, particularly crystalline high melting polyesters, have high melt viscosities, resulting in inferior flow and wetting properties and, therefore, must be applied at relatively high temperatures when used as hot melt adhesives.

ln US. Pat. No. 3,657,389, hot melt adhesive blends of poly( tetramethylene terephthalate) and polystyrene are disclosed. The adhesion to certain metals of the polyester of particular inherent viscosity (I.V.) is increased by the addition of polystyrene. A similar I.V. poly(tetramethylene terephthalate) modified with -20 mole percent dimer acid has low adhesion on metals, but a dramatic increase in adhesion, especially to uncoated steel, occurs when this dimer acid-modified polyester is blended with polystyrene.

Our copending application Ser. No. 280,930 filed Aug. .14, 1972 (now U.S. Pat. No. 3,795,644) is directed to dimer acid-modified poly(tetramethylene terephthalate) blended with vinyl aromatic polymers. This composition has a relatively low melt viscosity and improved adhesion to metals. Our copending Application Ser. No. 425,046 filed Dec. 14, 1973, which is a continuation-in-part of our aforesaid Ser. No. 280,930 is directed to dimer acidmodified polyesters derived from terephthalic acid and C -C glycols blended with vinyl aromatic polymers. Furthermore, US. Pat. No. 3,650,999 discloses poly(ester-amide) block copolymer hot melt adhesives. We have now found that by blending certain poly(ester-amide) block copolymers with vinyl aromatic polymers, preferably polystyrene,

the bond aging characteristics, particularly with respect to uncoated steel substrates, are very significantly improved.

It is, therefore, an object of this invention to provide hot melt adhesives having good adhesion to various types of substrates, especially metals.

A still further object is to provide hot melt adhesive compositions capable of maintaining high adhesive strength upon aging as well as the ability to maintain high bond strengths under relatively high temperature conditions.

A still further object is to provide laminated articles consisting of various substrates bonded with these compositions.

Another object of this invention is to provide hot melt adhesives derived from a blend of certain poly(ester-amides) and vinyl aromatic polymers.

Other objects are apparent elsewhere in this specification.

These objects have been obtained in accordance with the present invention by blending from about 5 to about 40 (preferably about 5 to about 25) percent by weight of a vinyl aromatic polymer with about 95 to about 60 (preferably about 95 to about percent by weight of a poly(esteramide). The poly(ester-amide) may be prepared by reacting a crystalline polyester prepolymer and an amorphous polyamide prepolymer.

The poly(ester-amide) contains from about 45 to about weight percent (preferably about 50 to about 80) of segments derived from a crystalline polyester and from about 5 to about 55 weight percent (preferably about 20 to about 50) weight percent of amorphous polyamide.

The polyester reactant is considered to be a prepolymer in view of the fact that it copolymerizes with the other reactants to form a block copolymer. The polyester must be capable of contributing a crystalline structure to the resulting poly(ester-amide) as is evidenced by a crystalline melting point as determined by differential thermal analysis (DTA) and/or differential scanning calorimetry (DSC) methods. Moreover, the polyester should have a melting point higher than 145C. and preferably in the range of 200C. to 300C. and an inherent viscosity of at least 0.1 and preferably in the range of from 0.2 to 0.5 when measured at 25C. using 0.50 gram of polymer per ml. of a solvent consisting of 60 percent by weight phenol and 40% by weight tetrachloroethane.

The polyester preferably is derived from A. a glycol component, at least about 80 mole per cent of which is a glycol having from 2 to 10 carbon atoms. Other glycols, aliphatic or alicyclic, straight or branched chain, containing 11 to 40 carbon atoms may also be included in the glycol component in amounts not exceeding about 20 mole per cent. Most desirably, substantially all of the glycol component is a glycol having from 2 to 6 carbon "atoms; and

(B) an acid component of dicarboxylic acid containing from 2 to 20 carbon atoms, at least about 80 -mole percent of which is terephthalic acid. Other dicarboxylic acids, aliphatic, aromatic or alicyclic, containing from 2 to 20 carbon atoms may also be included in this component in amounts not exceeding about 20 mole percent.

Although up to about 20 mole percent of the glycols and dicarboxylic acids other than glycols containing from 2 to 10 carbon atoms and terephthalic acid, may be used in the copolyester component of this invention if desired, it is preferred that the glycol and dicarboxylic acid portion be essentially a 2 to 10 carbon glycol and terephthalic acid. Other suitable glycols are alicyclie and aliphatic glycols containing from 1 1 to 40 carbon atoms. The carbon chain may be straight or banched. Examples of such glycols include ethylene glycol; 1,6-hexanediol; 1,10-decanediol; 2,2-dimethyl- 1 ,3-propanediol; 1,4-cyclohexanedimethanol; 1,4- cyclohexanediol; diethylene glycol; triethylene glycol and dimer glycol. Other suitable dicarboxylic acids are straight and branched chain aliphatic, alicyclic and aromatic acids containing from 2 to 20 carbon atoms including maleic, dimethylmalonic, adipic, 2-

methyladipic, azelaic, sebacic, isophthalic, hexahydroterephthalic, hexahydroisophthalic, trans-l,4 cyclohexanedicarboxylic, 2,5-norbornanedicarboxylic and oxydipropionic acid.

The amide portion of the poly( ester-amide) adhesive compositions of this invention are amorphous block segments which contribute wettability, elasticity and rubber character to the adhesive composition. The polyamide portion of the poly(ester-amide) compositions of the present invention is the reaction product of a dimer acid and an aliphatic primary diamine.

The term dimer acid as used herein refers to a 36 carbon atom, long chain aliphatic dicarboxylic acid. The preparation and structure of the dimer acids is described in Journal of American Oil Chemists Society, 39, 534*545 1962). It is generally prepared by dimerizing an unsaturated fatty acid containing 18 carbon atoms such as linoleic or linolenic acid or a monohydric alcohol ester thereof. It is recognized in the art that dimer acids are chemicals of unique properties. Several different grades of dimer acids are available commercially which vary in monomer and trimer content and iodine value. For example, dimer acid is available from Emery lr'idustries, Inc. Preferably, the dimer acid used in this invention is substantially free of monomer and trimer fractions, which can be accomplished by distillation. Preferably, the dimer acid content is atv least 95 percent; The dimer acid may be used in its hydrogenated or unhydrogenated form. 3 The aliphatic primary diamines used in this invention contain from 2 to lO carbon atoms. Examples include ethylene diamine, tetramethylene diamine, nonamethylene diamine, decamethylene diamine, 1,3-propane diamine, l,5-pentane diamine, hexamethylene diamine, cyclohexylene diamine, etc. The preferred diamine is 1,6-hexane diamine.

Useful copolyamide segment variations may be obtained by modifying the preferred polyamide segment with up to 25 weight percent (based on total acid con tent) of other aliphatic dicarboxylic acids containing 6 to 20 carbon atoms. Examples of such acids include sebacid, suberic, adipic, azelaic, and pimelic acids. The poly(ester-amide) compositions of the present invention are further characterized as having an inherent viscosity of at least 0.3 and more preferably from 0.4 to 0.7. The crystalline melting point of these materials, as measured by DTA or DSC, is in the range of from about 100C. to 300C.

The poly(ester-amide) is prepared by a one-step or two-step method. In the'one-step method the acid and amine components, which go to form the polyamide segment, are polymerized in the presence of the crystalline polyester prepolymer. In the two step method, the polyamide and polyester prepolymer segments are prepared separately and then reacted together to form the poly(ester-amide). These methods are discussed in greater detail in the working examples set forth below.

The vinyl aromatic polymers used in the adhesive blends of the invention are prepared by conventional procedures from the corresponding monomers and contain at least 50 weight percent of polymer units derived from at least one monomer having the formula:

to 50 weight percent of polymer units derived from one or more of the following: olefins containing up to 12 carbon atoms (e.g., ethylene, propylene, butene, 4- methylpentene), butadiene, vinylnaphthalene, divinylbenzene, alkyl esters of acrylic and methacrylic acids wherein the alkyl groups contain from 1 to 4 carbons, acrylonitrile, methacrylonitrile, maleic anhydride, vinyl acetate, and ohter polymerizable compounds containing a CH=C group and which give copolymers which are stable under the extrusion and bonding conditions. Polystyrene is the preferred vinyl aromatic pol-' ymer. The inherent viscosity of the vinyl aromatic polymers used in the blends of the invention may vary from about 0.1 to 0.8 or more, but the preferred inherent viscosity is about 0.5 to 0.8.

The polyester prepolymer of this invention is prepared by conventional techniques, for example, by ester interchange of the selected glycol with the di methyl ester of terephthalic acid.

Blending of the poly(ester-amides) with the vinyl polymers may be carried out by various common procedures, including mechanical mixing of the particles, blending on hot rolls, mixing in the melt, or-mixing in solution and then removing the solvent. A satisfactory procedure is to stir the two polymers together under an inert atmosphere in a flask immersed in a metal bath. A preferred method is to blend the polymer in powder or granular form and extrude with a screw-type extruder.

Substances which may be laminated by the adhesives of this invention include metals (such as steel, iron, aluminum, chromium, copper, brass, bronze, nickel, zinc, titanium, and tin), wood, glass, ceramic materials, paper, cardboard, and fabrics. Substrates coated with a synthetic resin such as polyepoxide resin, epoxyphenolic resin, melamine resin, phenolic resin, alkyd resin, a vinyl, or an acrylic coating also may be laminated with the blends of this invention. The same or different materials may be laminated in one structure. It is generally advisable to clean the surfaces of the components to be laminated just prior to formation of the melt adhesive bonds to remove foreign matter grease, oxide coatings, etc., which might interfere with the formation of strong bonds.

The adhesive may be applied in molten form with a spatula or regular extrusion equipment to the surfaces of the components to be laminated. Alternatively, a film of the polyester (2 to 6 mils in thickness) may be placed between the surfaces. After application of the polyester, the surfaces are clamped together with a pressure of several pounds per square inch and heat is applied by placing the clamped structure in a forced-air oven about 20 to 50C. above the softening range of the adhesive. A convenient way of bonding metal test strips for peel tests is to heat them together on a hot plate while rubbing back and forth with a wooden spatula. No additional pressure is necessary. A glue line (adhesive thickness) of 3 to 5 mils is satisfactory.

Fillers, pigments, processing aids, and glass cloth may be incorporated in the adhesive layer to increase the bonding strength and temperature resistance. Fillers and pigments, such as very finely divided silica, alumina, or calcium carbonate, also affect the degree of crystallinity and the size of the crystallites. From lto 30% by weight may be added. Additives or processing into /s-inch pellets which are used to prepare the adhesive bonds. The vinyl aromatic polymer used in the adhesive blends of Tables 1, 2, and 3 is polystyrene having an l.V. of 0.72.

terephtlialate) aids may be used to further decrease the melt viscosity The T-peel strengths are determined on 6-mil, tinof the blends for more case of application. Such profree steel' (TF-steel) in accordance with ASTM D1876 cessing aids are disclosed in US. Pat. No. 3,644,267, but using precut (l-inch wide) specimens. The metal and terphenyl is preferred. Antioxidants and stabilizers specimens are first degreased by washing three times in also may be incorporated in the polymers to improve a detergent solution of Alconox (Alconox, Inc.) and the thermal and oxidative stability at elevated temperal0 rinsing in water each time. The metal specimens are tures. then rinsed in acetone and allowed to air dry.

The examples which follow are submitted for a better To prepare an adhesive bond, a specimen is heated understanding of the invention. sufficiently on a hot plate for the blend to melt (applied Parts and percentages are by weight and temperaas 20-mesh to As-inch particles or by rubbing a large tures are in degrees Centigrade unless otherwise specipiece back and forth). A hot plate temperature of fied. All inherent viscosities are determined at 25C. 280C. is used. After the molten polymer is evenly using 0.50 gram of polymer per 100 ml. of a solvent spread on the specimen over a 2-inch length with a consisting of 60 percent by weight phenol and 40 perwooden spatula, the top piece of metal is pressed cent by weight tetrachloroethane. against the sample. The sample is then turned over on In the examples, all poly( ester-amides) are prepared the hot plate with the second metal strip against the hot by the following procedure: plate surface. Heating is continued while the wooden The amorphous polyamide segment of the block spatula is rubbed back and forth over the adhesive area poly(ester-amide) is first prepared by heating and stiruntil a smooth, even glue line is obtained (about 20 secring the diamine(s), the dimer acid, and in some cases, onds). Then the specimen is placed on the laboratory a second aliphatic dicarboxylic acid at 190-220C. for bench and rubbing continued about 10 seconds longer about 1 hour at 100-150 psi. The reaction vessel is then while the adhesive cools. This method of forming the vented, and the calculated amount of crystalline polyadhesive bonds gives reproducible results similar to ester segment (LV. 0.1-0.5) is added. The reaction vesthose obtained by clamping the specimens together and Se] is then heated slowly to 260280C. over a period heating in a forced-air oven 20-50C. above the polyof an hour under nitrogen at 40-60 psi. and maintained mer melting point. Glue lines are about 3 to 5 mils in under these conditions for about 30 minutes. The reacthickness. tion vessel is then vented and vacuum is applied. The All bond aging tests are carried out in a forced-air, reaction is continued under full vacuum (0.2 to 5 mm. convectionheated oven at 100C. ilC. for 24 hours. of Hg) for 2-4 hours. The molten poly(esteramide) is The specimens are allowed to cool to room temperathen discharged under pressure into water and ture (25C.) before testing. quenched. The inherent viscosity of the amber poly- The polyamide block of the block poly(ester-amides) mers obtained is about 0.4-0.8. used in the examples of Table l is derived from dimer The poly(ester-amide)/vinyl aromatic polymer acid and hexamethylene diamine. This table illustrates blends are prepared by mixing 2 to 3-mm. particles of the effect of polystyrene content on the bond aging the two polymers and melt extruding them at characteristics of poly(ester-amide)lpolystyrene 200240C. into a small rod. The rod is then chopped blends.

TABLE 1 Poly(ester-amide) T-Peel, Lb./ln. Width, on Polyester Segment Polystyrene Steel at 23C. After Aging Example Composition Wt.% Final l.V. Content, Wt. Unaged 1 Day at [00C.

1 (Control) Poly(ethylene 0.60 0 28 16 terephthalate 2 Poly( ethylene 50 0. 5 27 19 te rephthalate I 3 Poly(ethylene 50 0.60 10 26 21 terephthalate) 4 Poly(ethylene 50 0.60 20 27 28 terephthalate 5 Poly(ethylene 50 0.60 40 21 17 terephthalate) 6 (Control) Poly(ethylene 60 0.65 0 24 4 terephthalate) 7 Poly(ethylene 60 0.65 5 30 7 terephthalate) 8 Poly(ethylene 60 0.65 10 37 l 1 terephthalate) 9 Poly(ethylene 60 0.65 20 30 I6 terephthalate) l0 Poly(ethylene 60 0.65 40 23 l5 terephthalate) ll (Control) Poly(ethylene 0.67 0 4 2 terephthalate) l 2 Poly( ethylene 70 0.67 5 24 6 terephthalate I l3 Poly( ethylene 70 0.67 10 27 6 terephthalate) l4 "Poly(ethylene 70 0.67 I 20 29 9 tereph'thala'te) i l5 Polytethylene 70 0.67 40 18 9 TABLE l-continued Poly( ester-amide) Polyester Segment Polystyrene Content, Wt. 7(-

T-Peel, Lb./ln. Width, on Steel at 23C. After Aging Unaged 1 Day at lC.

16 (Control) Poly( ethylene 80 terephth'alate) 17 Poly( ethylene 80 tercphthalate) Poly( ethylene terephthalale) Poly( ethylene terephthalate) Poly( ethylene terephthalate) Poly( ethylene terephthalate) Poly( ethylene terephthalate) Poly( ethylene terephthalate) Poly( tetramethylenc terephthalate) Poly( tetramethylene terephthalate) Poly( tetramethylene terephthalate) Poly( tetramethylene te rephthalate Poly( tetramethylene terephthalate) Poly( tetramethylene 80/20 tercphthalate/isophthalate) Poly( tetramethylene 80/20 terephthalate/isophthalate) Poly( tetramethylene 80/20 terephthalate/isophthalate) Poly( tetramethylene 80/20 terephthalate/isophthalate) Poly( tetramethylenc 80/20 terephthalate/isophthalate) Copoly( 80/20 tetra methylene/ethylene terephthalate) Copoly( 80/20 tetramethylene/ethylene terephthalate) Copoly( 80/20 tetramethylene/ethylene terephtha late) Copoly( 80/20 tetramethylene/ethylene terephthalate) Copoly(80/2O tetramethylene/ethylene terephthalate) Poly( hexamethylene terephthalate) Poly( hexamethylene terephthalate Poly( hexamethylene terephthalate Poly( hexamethylene terephthalate) Poly( hexamethylene terephthalate) 21 (Control) 95 0.66

24 (Control) 50 0.63

(Control) 60 0.68

(Control) 60 0.64

(Control) 60 0.72

l0 IO The examples of Table 1 illustrate the improved T- 60 peel strengths which are obtained in all cases after accelerated bond aging of the poly(ester-amide )lpolystyrene blends of the invvention, when compared to the T-peel strengths of the respective poly(ester-amides) alone. These examples also illustrate that; in most cases, the T-peel strengths even before bond aging of the block poly(ester-amides) on the steel substrate are significantly improved by the addition of only a very small amount of polystyrene.

Examples 44-48 of Table 2 which follows illustrate the improved bond aging characteristics which are obtained when polystyrene is blended with a block poly(ester-amide) which is comprised of 60 weight percent of polyester blocks of poly(ethylene terephthalate) and 40 weight percent of polyamide blocks derived from dimer acid and ethylene diamine, instead of hexamethylene diamine. The l.V. of the block poly(ester-amide) is 0.64.

TABLE 2 Poly T-Pccl; LbJ/ln. Width. on styrene Steel at 23C. After Bond Aging Example Content, Unaged 1 Day at 100C.

44 (Control) 1 l6 3 45 5 l9 7 46 g 10 23 12 47 '20 20 ;l 3 4 4o 7 8 Examples 49-53 of Table 3 which follows illustrate the improved bond aging characteristics which are obtained when polystyrene is blended with a block poly(ester-amide) which is composed of 60 weight percent of polyester blocks of poly(ethylene terephthalate) and40 weight percent of copolyamide blocks derived from hexamethylene diamine and a 75/25 weight ratio of dimer/sebacic acids. The l.V. of the block poly( esteramide) is 0.69.

TABLE 3 Poly- T-Peel, LbJIn. Width, on styrene Steel at 23C; After Bond Aging Example 1 Content, Unaged 1 Day at l00C.

49 (Control) 0 4 50 5 24 7 5 1 1O 27 14 52 20 25 13 53 40 26 10 Examples 54 through 63 of Table 4 which follows illustrate the effects on the T-peel strength at 23C. before and after bond aging for 1 day at 100C. on tin-free steel (TF-steel) of (a) the LV. of the polystyrene, inv cluding copolymers, and (b) the composition of the poiystyrene copolymer. The block poly(ester-amide) used in the blends of these examples contains 60 weight percent of poly(ethylene terephthalate) segments and weight percent of segments of the amorphous polyamide of dimer acid and hexamethylene diamine. The 40 W. of the block poly(esteramide) is 0.65.

TABLE 4 10 a. from about 95 to about 60 percent by weight of a poly(steramide) block copolymer having from about to about 95 percent by weight of crystalline polyester segments derived from at least one aliphatic or alicyclic glycol having from 2 to 10 car bon atoms and at least one dicarboxylic acid having from 2 to 20 carbon atoms, and from about 55 to about 5 percent by weight of amorphous polyamide segments derived from a dimer acid and an ali- 10 phatic primary diamine containing 2 to 10 carbon atoms, and

b. from about 5 to about 40 percent by weight of a vinyl aromatic polymer of which at least percent by weight of its polymeric units are derived from at 15 least one monomer having the formula wherein R is hydrogen or an alkyl group containing 1 to 4 carbon atoms and R is hydrogen, chlorine,

25 phenyl or an alkyl group containing 1 to 4 carbon atoms. 2. An adhesive composition according to claim 1 wherein said vinyl aromatic polymer is polystyrene.

3. An adhesive composition according to claim 1 0 wherein said dicarboxylic acid is at least 80 percent ter- T-Peel on Steel at 23C., LbJ ln. Width Polystyrene Polymer or Copolymer Amt. Aged 1 Day Example Comonomer [.V. Wt. Unaged at l00C.

54 (Control 0 24 4 55 None 0.10 20 28 12 56 None 0.28 20 30 15 57 None 0.58 20 32 13 58 None 0.72 20 30 16 59 l0 wt. Acrylcnitril 0.65 20 29 10 60 [2 wt. a-Methylstyrene 0.56 20 30 13 61 i 20 wt. Butadiene 0.8l 20 26 12 62 5 wt. Methyl acrylate 0.52 20 24 9 63 15 wt. Vinyl acetate 0.73 20 22 8 amide) and about 5 to about 25 percent vinyl aromatic polymer.

. 7. An adhesive composition comprising 60 a. from about to about 95 percent by weight of a poly(esteramide) having from about 50 to about percent by weight of crystalline polyester segments derived from at least one aliphatic or alicyclic glycol having from 2 to 6 carbon atoms and at least 65 one dicarboxylic acid, at least 80 percent of which is terephthalic, and from about 50 to about 20 per cent by weight of amorphous polyamide segments derived from a dimer acid and 1,6-hexanediamine,

1 1 b. from about 25 to about percent by eight. of a vinyl aromatic polymer of which at leastSOpercent by weight of its polymeric units are derived from at least one monomer having the formula wherein R is hydrogen or an alkyl group containing 1 to 4 carbon atoms and R is hydrogen, chlorine, phenyl or an alkylgroup containing l to 4 carbon atoms.

8. An adhesive composition according to claim 7 wherein said vinyl aromatic polymer is polystyrene.

9. An article of manufacture comprising a pair of substrates bonded togetherwith a composition comprising a. from about 95 to about 60 percent by weight of a poly(ester-amide) block copolymer having from about 45' to about 95 percent by weight of crystalline polyester segments derived from at least one aliphatic or "alicyclic glycol having from 2 to carbon atoms and at least one dicarboxylic acid having I from 21b carbon atoms, and from about 55 to about 5 percent by weight of amorphous polyamide segments derived from a dimer acid and an aliphatic primary diamine containing 2 to 10 carbon atoms, and

b. from about 5 to about 40 percent by weight of a vinyl aromatic polymer of which at least 50 percent by weight of its polymeric units are derived from at least one monomer having the formula R-FCHz I wherein R is hydrogen or an alkyl group containing 1 to 4 carbon atoms and R is hydrogen, chlorine, phenyl or an alkyl group containing 1 to 4 carbon atoms. 10. An article of manufacture according to claim 9 wherein said vinyl aromatic polymer is polystyrene.

11. An article of manufacture according to claim 9 wherein said dicarboxylic acid is at least 80 percent terephthalic acid.

12. An article of manufacture according to claim 9 wherein said diamine is 1,6-hexanediamine.

13. An article of manufacture according to claim 9 wherein said poly(ester-amide) has from about 50 to about 80 percent by weight crystalline polyester segments and from about 50 to about 20 percent by weight amorphous polyamide segments.

14. An article of manufacture according to claim 9 wherein said composition comprises about 95 to about percent poly(ester-amide) and about 5 to 25 percent vinyl aromatic polymer.

15. An article of manufacture comprising a pair of substrates bonded together with a composition comprising a. from about 75 to about 95 percent by weight of a poly(ester-amide) having from about 50 to about percent by weight of crystalline polyester segments derived from at least one aliphatic or alicyclic glycol having from 2 to 6 carbon atoms and at least one dicarboxylic acid, at least 80 percent of which is terephthalic, and from about 50 to about 20 percent by weight of amorphous polyamide segments derived from a dimer acid and l,6-hexanediamine,

b. from about 25 to about 5 percent by weight of a vinyl aromatic polymer of which at least 50 percent by weight of its polymeric units are derived from at least one monomer having the formula wherein R is hydrogen or an alkyl group containing 1 to 4 carbon atoms and R is hydrogen, chlorine, phenyl or an alkyl group containing 1 to 4 carbon atoms.

16. An article according to claim 15 wherein said vinylaromatic polymer is polystyrene.

17. The method of bonding a pair of substrates together comprising applying evenly to at least one of said substrates the molten composition of claim 1, pressing the substrates together with adhesive in the middle, and allowing said substrates to cool.

18. The method of bonding a pairof substrates together comprising applying evenly to at least one of said substrates the molten composition of claim 15, pressing the substrates together with adhesive in the middle and allowing said substrates to cool. 

1. AN ADHESIVE COMPOSITION COMPRISING A. FROM ABOUT 95 TO ABOUT 60 PERCENT BY WEIGHT OF A POLY(ESTERAMIDE) BLOCK COPOLYMER HAVING FROM ABOUT 45 TO ABOUT 95 PERCENT BY WEIGHT OF CRYSTALLINE POLYESTER SEGMENTS DERIVED FROM AT LEAST ONE ALIPHATIC OR ALICYCLIC GLYCOL HAVING FROM 2 TO 10 CARBON ATOMS AND AT LEAST ONE DICARBOXYLIC ACID HAVING FROM 2 TO 20 CARBON ATOMS, AND FROM ABOUT 55 TO ABOUT 5 PERCENT BY WEIGHT OF AMORPHOUS POLYAMIDE SEGMENTS DERIVED FROM A DIMER ACID AND AN ALIPHATIC PRIMARY DIAMINE CONTAINING 2 TO 10 CARBON ATOMS, AND B. FROM ABOUT 5 TO ABOUT 40 PERCENT BY WEIGHT OF A VINYL AROMATIC POLYMER OF WHICH AT LEAST 50 PERCENT BY WEIGHT OF ITS POLYMERIC UNITS ARE DERIVED FROM AT LEAST ONE MONOMER HAVING THE FORMULA
 2. An adhesive composition according to claim 1 wherein said vinyl aromatic polymer is polystyrene.
 3. An adhesive composition according to claim 1 wherein said dicarboxylic acid is at least 80 percent terephthalic acid.
 4. An adhesive composition according to claim 1 wherein said diamine is 1,6-hexanediamine.
 5. An adhesive composition according to claim 1 wherein said poly(ester-amide) has from about 50 to about 80 percent by weight crystalline polyester segments and from about 50 to about 20 percent by weight amorphous polyamide segments.
 6. An adhesive composition according to claim 1 comprising about 95 to about 75 percent poly(ester-amide) and about 5 to about 25 percent vinyl aromatic polymer.
 7. An adhesive composition comprising a. from about 75 to about 95 percent by weight of a poly(esteramide) having from about 50 to about 80 percent by weight of crystalline polyester segments derived from at least one aliphatic or alicyclic glycol having from 2 to 6 carbon atoms and at least one dicarboxylic acid, at least 80 percent of which is terephthalic, and from about 50 to about 20 percent by weight of amorphous polyamide segments derived from a dimer acid and 1,6-hexanediamine, b. from about 25 to about 5 percent by weight of a vinyl aromatic polymer of which at least 50 percent by weight of its polymeric units are derived from at least one monomer having the formula
 8. An adhesive composition according to claim 7 wherein said vinyl aromatic polymer is polystyrene.
 9. An article of manufacture comprising a pair of substrates bonded together with a composition comprising a. from about 95 to about 60 percent by weight of a poly(ester-amide) block copolymer having from about 45 to about 95 percent by weight of crystalline polyester segments derived from at least one aliphatic or alicyclic glycol having from 2 to 10 carbon atoms and at least one dicarboxylic acid having from 2 to 20 carbon atoms, and from about 55 to about 5 percent by weight of amorphous polyamide segments derived from a dimer acid and an aliphatic primary diamine containing 2 to 10 carbon atoms, and b. from about 5 to about 40 percent by weight of a vinyl aromatic polymer of which at least 50 percent by weight of its polymeric units are derived from at least one monomer having the formula
 10. An article of manufacture according to claim 9 wherein said vinyl aromatic polymer is polystyrene.
 11. An article of manufacture according to claim 9 wherein said dicarboxylic acid is at least 80 percent terephthalic acid.
 12. An article of manufacture according to claim 9 wherein said diamine iS 1,6-hexanediamine.
 13. An article of manufacture according to claim 9 wherein said poly(ester-amide) has from about 50 to about 80 percent by weight crystalline polyester segments and from about 50 to about 20 percent by weight amorphous polyamide segments.
 14. An article of manufacture according to claim 9 wherein said composition comprises about 95 to about 75 percent poly(ester-amide) and about 5 to 25 percent vinyl aromatic polymer.
 15. An article of manufacture comprising a pair of substrates bonded together with a composition comprising a. from about 75 to about 95 percent by weight of a poly(ester-amide) having from about 50 to about 80 percent by weight of crystalline polyester segments derived from at least one aliphatic or alicyclic glycol having from 2 to 6 carbon atoms and at least one dicarboxylic acid, at least 80 percent of which is terephthalic, and from about 50 to about 20 percent by weight of amorphous polyamide segments derived from a dimer acid and 1,6-hexanediamine, b. from about 25 to about 5 percent by weight of a vinyl aromatic polymer of which at least 50 percent by weight of its polymeric units are derived from at least one monomer having the formula
 16. An article according to claim 15 wherein said vinyl aromatic polymer is polystyrene.
 17. The method of bonding a pair of substrates together comprising applying evenly to at least one of said substrates the molten composition of claim 1, pressing the substrates together with adhesive in the middle, and allowing said substrates to cool.
 18. The method of bonding a pair of substrates together comprising applying evenly to at least one of said substrates the molten composition of claim 15, pressing the substrates together with adhesive in the middle and allowing said substrates to cool. 